Orbital Sciences will not use Soviet-era NK-33 rocket engines after Antares failure

U.S. company Orbital Sciences has published the first results of an investigation into the October 29 failure of its Antares launch vehicle, tasked with lofting the Cygnus cargo carrier to the International Space Station, and has adjusted plans concerning the fulfillment of its contract with NASA.

U.S. company Orbital Sciences has published the first results of an investigation into the October 29 failure of its Antares launch vehicle, tasked with lofting the Cygnus cargo carrier to the International Space Station, and has adjusted plans concerning the fulfillment of its contract with NASA.

According to a press release, which was published on the corporation's website on Wednesday, "preliminary evidence and analysis conducted to date points to a probable turbopump-related failure in one of the two Aerojet Rocketdyne AJ26 stage one main engines," originally NK-33 engines built in Russia for the Soviet-era N-1 moon rocket.

"As a result, the use of these engines for the Antares vehicle likely will be discontinued," the press release says.

The corporation adopted a decision to "accelerate an upgrade of the Antares medium-class launcher's main propulsion system" in order to "fulfill its contract commitments under NASA's Commercial Resupply Services (CRS) program," the document says.

"Under the new approach and in line with Orbital's existing CRS contract, all remaining cargo will be delivered to the International Space Station by the end of 2016," it says.

All further flights to the ISS will be conducted using a rocket equipped with a new engine.

Orbital develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers. The company's primary products are satellites and launch vehicles.

The unmanned Antares launch vehicle carrying a Cygnus cargo ship for the ISS exploded immediately after liftoff at NASA's Wallops Flight Facility in Virginia early on October 29.